Malicious PDF — malware analysis report

Static analysis result for SHA-256 a90b128d9be17090…

MALICIOUS

PDF

66.1 KB Created: 2021-09-28 07:34:32 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-25
MD5: dcbd1ad79fc5d26e42086c047dd1f477 SHA-1: abaf6cf2f46bb14c02c07d7e57b7f616818d6898 SHA-256: a90b128d9be170902ef366b0b150241adbb801d80ca55a3a027e9ecc5b2bbe3e
146 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF is identified as a phishing lure due to its small size and image-heavy content, typical of a screenshot designed to hide clickable links. Multiple heuristics indicate it functions as a link farm on disposable hosting, directing users to various external URLs. The ClamAV detection and ML classifier strongly suggest malicious intent, likely to redirect users to phishing or malware sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9975

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • Image-only document with action trigger (screenshot lure) medium PDF_IMAGE_LURE
    PDF has 1 image(s), only 0 text block(s), carries a click-outward action, and is only 66 KB — typical shape of a phishing lure where a full-page screenshot hides a clickable button that launches or submits to an attacker URL.
  • Small PDF is a non-clustered link farm on disposable hosting medium PDF_SEO_DISPOSABLE_LINK_FARM
    Small PDF contains many clickable external PDF links spread thin across many distinct hosts (no single dominant host), corroborated by a utm_term SEO-redirector link and/or links parked on free/disposable content hosts. This is the 'free document/template' SEO phishing PDF family, which ranks for search queries and routes users into payload/redirect chains, rather than a normal document citation pattern. The PDF itself carries no exploit — the risk is the linked destinations.
  • External URI info PDF_URI
    PDF contains an external URL action
  • Object number defined twice with different bodies info PDF_DUPLICATE_OBJ_BODY_INCREMENTAL
    The same indirect object (N G) is defined more than once with different body bytes. First-wins and last-wins readers will resolve different content, which is a parser-confusion shape used by targeted PDFs. Body-only differences are common in benign incremental updates, so severity is raised only when the duplicate carries active content.
  • Embedded URL info EMBEDDED_URL
    One or more URLs were extracted from the document. The URL itself is not a detection — see the per-URL labels for which channel (macro, JS, link annotation, document body, ...) reached each URL.
    URL https://allytemp.ru/uplcv?utm_term=porn+on+mobdro PDF link annotation
    • http://www.combatsim.eu/wp-content/plugins/formcraft/file-upload/server/content/files/161345b1e63d00---21837507338.pdfIn PDF document text
    • http://strap.sk/uploads/files/32676491671.pdfIn PDF document text
    • http://jca-t.com/fck_image/file/51350429596.pdfIn PDF document text
    • http://acudrved.com/ckfinder/userfiles/files/wefoni.pdfIn PDF document text
    • http://engelholm.boj.se/uploads/userfiles/files/56729291421.pdfIn PDF document text
    • http://www.emporiocaritaspisa.it/wordpress/wp-content/plugins/formcraft/file-upload/server/content/files/1613a1f84d7790---wifefexowona.pdfIn PDF document text
    • https://gbagencement.fr/uploads/file/90650636083.pdfIn PDF document text
    • http://artkulinaria.pl/sites/default/files/file/razujadasufujeladulegit.pdfIn PDF document text
    • http://jessie.vn/images/ckeditor/files/laxazajibi.pdfIn PDF document text
    • http://airzo.net/userData/board/file/zuzakanazev.pdfIn PDF document text
    • http://club-integra.ru/userfiles/file/romirasemevivezabazepiw.pdfIn PDF document text
    • https://tadimtursu.com/image/files/36097612092.pdfIn PDF document text
    • https://phatgiaolongan.com/upload/ckupload/files/85890450293.pdfIn PDF document text
    • https://www.servicespace.org/inc/ckfinder/userfiles/files/3559522549.pdfIn PDF document text
    • http://ambvet-trefontane.eu/userfiles/files/pevexezezurefonupilun.pdfIn PDF document text
    • https://rajaunited.com/contents/files/tokajulazumaga.pdfIn PDF document text
    • https://artinterior.bg/userfiles/file/7728790786.pdfIn PDF document text
    • http://www.lbf-cosmetics.com/website/wp-content/plugins/formcraft/file-upload/server/content/files/1613eab108f605---77265006349.pdfIn PDF document text
    • http://hasanmasat.com/ckfinder/userfiles/files/33119185222.pdfIn PDF document text
    • https://ardiinerkh.mn/uploads/userfiles/files/16353966238.pdfIn PDF document text
    • http://syuncyoku.jp/upload/file/49198199830.pdfIn PDF document text
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#In PDF document text
    • http://purl.org/dc/elements/1.1/In PDF document text
    • http://ns.adobe.com/pdf/1.3/In PDF document text
    • http://ns.adobe.com/xap/1.0/In PDF document text
    • http://ns.adobe.com/xap/1.0/mm/In PDF document text
    • http://ns.adobe.com/xap/1.0/rights/In PDF document text
    • http://dejavu.sourceforge.netIn PDF document text
    • http://dejavu.sourceforge.net/wiki/index.php/LicenseIn PDF document text

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000aa22.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xAA22 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000c238.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC238 9852 bytes
SHA-256: 027013062448c294d98db7ba93fbfc15948dfa07b90d26d46df486f5d56dc8b3
font_02_sfnt_off0000d7b4.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD7B4 13892 bytes
SHA-256: 875c23c88ba9a41a392800cae081852b3c29bda1766df868d4cf7449021f300d